Is time travel possible? Short answer: Yes, and you’re doing it right now – hurtling into the future at the impressive rate of one second per second.
We are almost always moving through time at the same speed, whether you are watching paint dry or wishing you had more hours to visit with a friend.
However, this is not the kind of time travel that has captivated countless science fiction writers or spurred a genre so extensive that Wikipedia lists over 400 titles in the category “Movies about Time Travel.” In franchises like “Star Trek,” and “Back to the Future,” characters climb into some wild vehicle to blast into the past or spin into the future. Once the characters have traveled through time, they grapple with what happens if you change the past or present based on information from the future, (which is where time travel stories intersect with the idea of parallel universes or alternate timelines).
Although many people are fascinated by the idea of changing the past or seeing the future before it is due, no person has ever demonstrated the kind of back-and-forth time travel seen in science fiction or proposed a method of sending a person through significant periods of time that would not destroy them on the way. And, as physicist Stephen Hawking pointed out in his book “Black Holes and Baby Universes,” (in 1994), “The best evidence we have that time travel is not possible, and never will be, is that we have not been invaded by hordes of tourists from the future.”
Science does support some amount of time-bending, though. For example, physicist Albert Einstein’s theory of special relativity proposes that time is an illusion that moves relative to an observer. An observer traveling near the speed of light will experience time, with all its aftereffects, (boredom, aging, etc.), much more slowly than an observer at rest. That is why astronaut Scott Kelly aged ever so slightly less over the course of a year in orbit than his twin brother who stayed here on Earth.
There are other scientific theories about time travel, including some weird physics that arise around wormholes, black holes, and string theory. For the most part, though, time travel remains the domain of an ever-growing array of science fiction books, movies, television shows, comics, video games and more.
Time travel has long occupied a significant place in fiction. Since as early as the “Mahabharata,” an ancient Sanskrit epic poem compiled around 400 B.C., humans have dreamed of warping time.
Every work of time-travel fiction creates its own version of space-time, glossing over one or more scientific hurdles and paradoxes to achieve its plot requirements.
Some make a nod to research and physics, like “Interstellar,” a 2014 film directed by Christopher Nolan. In the movie, a character played by Matthew McConaughey spends a few hours on a planet orbiting a supermassive black hole, but because of time dilation, observers on Earth experience those hours as a matter of decades.
Because there are so many theories regarding time, its nature, and how to travel through it, there is no correct way to portray it. Some insist that any disruption to the timeline will “heal,” and all will be set back on course, but this is unlikely. If the person went back just to witness an event, they talked to no one, and received no more than a passing glance by others and were quickly forgotten, then we could see the future not changing … much. But even if something small happens, like the traveler buys a slice of pizza from a street vendor, it could initiate a chain of events that divert the future substantially. What about the person who was supposed to buy that slice? That person might then continue walking to find another vendor, and chat with a friend he met on the street. If that friend subsequently misses a train and arrives late to work, failing to smile at the woman who would have been his future wife, then generations of people will have ceased to exist in the future, and all of their actions, and achievements, will have been erased … just because of a slice of pizza.
This is another example of causality, and every major and minor moment in our lives can be traced back to equally minuscule events.
Let’s go with the easy to digest “sliding doors” concept. This theory is a cultural concept rather than a scientific law, originating from the 1998 film Sliding Doors. It describes how seemingly minor, chance events can drastically alter the trajectory of a person’s life, suggesting that our realities are built on a chain of coincidental “what if” moments.
The most interesting footnote of this premise is not the movie starring the insufferable Gwyneth Paltrow, but instead the actual event that transpired involving the aforementioned queen of Goop.
On the morning of the September 11 attacks, a pedestrian named Lara Lundstrom Clarke jaywalked across Seventh Avenue to the Christopher Street subway station in New York. She was halted by a stop-start traffic standoff with a silver Mercedes SUV carrying Paltrow.
The brief delay caused Clarke to miss her intended train. By the time she arrived at the World Trade Center via a later train, the first plane had already struck. Had she not been delayed, she would have been at her desk on the 77th floor of Tower 2.
Amazing sh*t, (truly)!
Your head starts to spin and does not stop if you spend too many moments contemplating all of this, so to end on a lighter note, I will quote Beetlejuice. Well, lyrics from the broadway hit:
Because the universe is random
Yes, but
Random for a reason!
Did You Know? If we ever invent a time machine to visit the past, we have to travel through space too. Earth spins and orbits the sun. If you just went back in time in the same exact spot, you would end up floating in empty space.